JP2009289944A - Capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitor capable of improving heat radiation characteristics of a capacitive element without causing cost rise and scale-up of the capacitor. <P>SOLUTION: The capacitor 1 has one or more capacitive elements 12; a housing body 10 housing the capacitive element(s) 12 and attached on a cooler 16; and a heat radiating member 14 for radiating heat from the capacitive element(s) 12 to the cooler side. The heat radiating member 14 is disposed on the capacitive element(s) 12 and inserted in the cooler 16 so that part of the heat radiating member 14 may contact a coolant circulating through the cooler 16, and anodization is applied to at least a portion (d) inserted in the cooler 16 of the heat radiating member 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a capacitor structure.

  Capacitors are basic electrical components used in various industrial equipment, including small and large ones. A typical capacitor includes a capacitor element in which electrodes are arranged on both sides of a dielectric layer and wound around them, and a container in which the capacitor element is accommodated.

  Normally, when a current is passed through the capacitor element, the capacitor element generates heat. If the heat dissipation characteristics of the capacitor element are poor, the temperature of the capacitor element rises, which may cause problems such as deterioration of the characteristics of the capacitor itself or a decrease in life. In order to improve such a problem, it is necessary to improve the heat dissipation characteristics of the capacitor element.

  FIG. 8 is a schematic cross-sectional view showing a configuration of a conventional capacitor. For example, in Patent Document 1, as shown in FIG. 8, a condenser 6 including a condenser element 32, a heat pipe 34, and a housing 36 that contains the condenser element 32 is installed in a cooler 38. The cooler 38 is formed with a cooling unit 40 serving as a refrigerant passage, and a refrigerant inlet and outlet (not shown). The heat pipe 34 has a function of releasing the heat of the capacitor element 32 to the cooler 38 side. The heat pipe 34 is installed in the core portion 42 of the capacitor element 32, and a part of the heat pipe 34 is inserted into the cooler 38. Has been. Note that the container 36 shown in FIG. 8 is fixed to the cooler 38 by a fastener 44 such as a bolt. Further, an O-ring 46 is provided between the container 36 and the cooler 38 so that the refrigerant flowing through the cooler 38 does not flow outside. With the above configuration, heat generated when a current is passed through the capacitor element 32 is transmitted to the refrigerant flowing through the cooling unit 40 via the heat pipe 34, and heat is released from the refrigerant to the outside. It is possible to improve the heat dissipation characteristics.

JP-A-11-329899 JP-A-11-204378 Japanese Utility Model Publication No. 63-36713 JP-A-7-201679 JP-A-64-80015

  However, in the capacitor of Patent Document 1, no electrical insulation measure is taken, and the heat pipe and the cooler, in particular, the refrigerant flowing through the cooling unit are electrically connected to each other, which may cause a short circuit of the capacitor, a leakage current, and the like. If an electrical insulation measure is simply taken, an insulating member such as an insulating sheet has to be arranged in a complicated manner, which raises a problem of increasing the cost and size of the capacitor.

  Accordingly, an object of the present invention is to provide a capacitor capable of improving the heat dissipation characteristics of the capacitor element without increasing the cost and size of the capacitor.

  The present invention is a capacitor having one or a plurality of capacitor elements, a container that houses the capacitor elements and is attached to a cooler, and a heat radiating member that releases heat from the capacitor elements to the cooler side. The heat dissipating member is installed in the capacitor element, and a part of the heat dissipating member is inserted into the cooler so as to be in contact with the refrigerant flowing through the cooler, and at least the cooling member of the heat dissipating member Alumite treatment is applied to the place where it is inserted into the chamber.

  In the capacitor, the capacitor element is preferably a wound type.

  Further, in the capacitor, the heat radiating member is installed on an end surface of the capacitor element, and the heat radiating member may be inserted into the cooler so that a part of the heat radiating member is in contact with the refrigerant flowing in the cooler. preferable.

  Further, in the capacitor, the heat dissipating member is installed between adjacent capacitor elements, and the heat dissipating member may be inserted into the cooler so that a part of the heat dissipating member is in contact with the refrigerant flowing in the cooler. preferable.

  Further, in the capacitor, the heat radiating member is installed in a core portion of the capacitor, and is inserted into the cooler so that a part of the heat radiating member is in contact with the refrigerant flowing in the cooler. Is preferred.

  Moreover, in the capacitor, it is preferable that a threaded portion is provided at a position of the heat dissipation member inserted into the cooler.

  Moreover, in the capacitor, it is preferable that an alumite treatment is performed on the threaded portion.

  In the capacitor, it is preferable that a sealing material is provided at the threaded portion.

  Moreover, it is preferable that the said capacitor | condenser is provided with the radiation fin in the location of the thermal radiation member penetrated in the said cooler.

  According to the present invention, the heat dissipation characteristics of the capacitor element can be improved without increasing the cost of the capacitor and increasing the size.

  Embodiments of the present invention will be described below.

  FIG. 1 is a schematic cross-sectional view illustrating an example of a configuration of a capacitor according to an embodiment of the present invention. As shown in FIG. 1, the capacitor 1 includes a container 10, a capacitor element 12, and a heat radiating member 14. Although not shown, the capacitor element is provided with a lead, and the lead is connected to a terminal (not shown) provided on the container.

  The container 10 houses one or a plurality of capacitor elements 12. The container 10 is attached to the cooler 16. Specifically, as shown in FIG. 1, the container 10 is fastened to the cooler 16 by a fastener 18 such as a bolt. Further, an O-ring 20 is provided between the container 10 and the cooler 16 so that the cooling water flowing through the cooler 16 does not flow outside. Examples of the material of the container 10 include resin materials such as polyphenylene sulfide, polybutylene terephthalate, and polyether ether ketone.

  The cooler 16 to which the container 10 is attached will be described. As shown in FIG. 1, the cooler 16 includes a cooling inlet (not shown), a cooling outlet (not shown), and a cooling unit 22 serving as a passage through which a refrigerant flows. In the cooler 16, the refrigerant introduced from the cooling inlet flows through the cooling unit 22 (for example, in the direction of the arrow shown in FIG. 1), and the refrigerant is discharged from the cooling outlet. Specific examples of the cooler 16 in the present embodiment include a cooling bus spa for cooling the condenser, a cooler for electronic equipment such as an inverter circuit using the condenser, and the like. It is preferable to use a cooler for an electronic device such as an inverter circuit in that the cost and the size of the device can be suppressed.

  As shown in FIG. 1, the heat radiating member 14 is installed on the capacitor element 12, and the cooling unit 22 of the cooler 16 is in contact with the refrigerant flowing through the cooling unit 22 of the cooler 16 while a part of the heat radiating member 14 is in contact with the refrigerant. It is inserted in. In order to allow the heat radiating member 14 to be inserted into the cooling portion 22 of the cooler 16, through holes through which the heat radiating member 14 passes are formed in the housing 10 and the partition walls (10 a, 16 a) of the cooler 16. The through hole formed in the partition wall 10a of the container 10 preferably has a diameter equivalent to the diameter of the heat radiating member 14 so that the refrigerant passing through the cooler 16 does not flow into the container 10. An O-ring (not shown) is preferably provided between the partition wall 10a in which the through hole is formed and the heat dissipation member 14. The through-hole formed in the partition wall 16a of the cooler 16 may have a diameter equivalent to the diameter of the heat radiating member 14, but has a diameter larger than the diameter of the heat radiating member 14 as shown in FIG. It is preferable that Thereby, since a refrigerant | coolant can be made to contact the accommodating body 10, the thermal radiation characteristic of the capacitor | condenser element 12 in the accommodating body 10 can be improved.

The heat radiating member 14 is subjected to alumite treatment. The alumite treatment may be performed on the entire heat radiating member 14, but at least a portion of the heat radiating member 14 exposed to the cooling unit 22 of the cooler 16 (d shown in FIG. 1) is subjected to the alumite treatment. Just do it. The heat radiating member 14 is formed by forming an aluminum layer on the surface of an aluminum material or a metal core material such as copper that can be anodized. Moreover, the heat radiating member 14 does not necessarily have a heat pipe structure. This is because the heat of the capacitor element 12 can be released to the cooler 16 side even when the aluminum layer or the aluminum core is formed on the surface of the metal core. The alumite treatment on the heat radiating member 14 is, for example, a treatment method in which an aluminum material is immersed in sulfuric acid, phosphoric acid, an oxalic acid aqueous solution, or the like, and electrolyzed (for example, current density 10 mA / cm ² ). By subjecting the aluminum material to an alumite treatment, an alumite film such as Al ₂ O ₃ is formed on the aluminum material, so that the electrical insulation is improved at the location where the alumite treatment is performed.

  When a current is passed through the capacitor element 12, the capacitor element 12 generates heat. In this embodiment, a part of the heat radiating member 14 installed in the capacitor element 12 is in contact with the refrigerant flowing in the cooler 16 (substantially the cooling unit 22). Therefore, the heat generated when the current is supplied to the capacitor element 12 is transmitted to the refrigerant flowing through the cooling unit 22 via the heat radiating member 14, and the heat is released from the refrigerant to the outside. Thereby, the heat dissipation characteristic of the capacitor element 12 can be improved. Moreover, in this embodiment, since the alumite process is performed to the location (specifically, the location which contacts a refrigerant | coolant) at least in the cooler 16 among the thermal radiation members 14, the thermal radiation member 14 and cooler 16, in particular, insulation with the refrigerant flowing through the cooling unit 22 is ensured. As a result, it is possible to suppress the occurrence of a short circuit and leakage current of the capacitor. In addition, in order to ensure insulation between the heat radiating member 14 and the refrigerant flowing through the cooler 16 and the cooling unit 22, it is not necessary to arrange an insulating material such as an insulating sheet in a complicated manner, thereby increasing the cost and size of the capacitor. Can be suppressed.

  The capacitor element 12 has a structure in which electrodes (anode and cathode) are arranged on both sides of a dielectric layer, and these are laminated or wound. The capacitor element 12 is easy to manufacture, has a structure that easily transfers the heat of the capacitor element 12 to the heat radiating member 14, and so on, electrodes (anode and cathode) are arranged on both sides of the dielectric layer. A wound type is preferred.

  Although the installation location of the heat dissipation member 14 in the capacitor element 12 is not particularly limited, it is preferably the end face of the capacitor element 12 as shown in FIG. By installing the heat dissipation member 14 on the end face of the laminated and wound capacitor element 12, the heat of the capacitor element 12 can be efficiently transmitted to the heat dissipation member 14. Further, when a metal layer (current collection layer) such as a metallicon is formed on the end face of the capacitor element 12, it is preferable to dispose the heat dissipation member 14 on the metal layer formed on the end face of the capacitor element 12.

  FIG. 2 is a schematic cross-sectional view showing another example of the configuration of the capacitor according to the embodiment of the present invention. In the capacitor shown in FIG. 2, the same reference numerals are given to the same components as those of the capacitor 1 shown in FIG. As shown in FIG. 2, the capacitor 2 includes a plurality of capacitor elements 12 a and 12 b housed in the housing body 10. A heat radiating member 14 is installed between adjacent capacitor elements 12 a and 12 b, and a part of the heat radiating member 14 is inserted into the cooler 16 so as to be in contact with the refrigerant flowing in the cooler 16. The heat radiating member 14 may be in contact with at least one of the adjacent capacitor elements 12a and 12b. When a plurality of capacitor elements are accommodated in the container, thermal interference between the capacitor elements may occur, causing deterioration of the capacitor elements. In this embodiment, since the heat of the capacitor element can be released to the cooler 16 side via the heat dissipation member 14 with the above configuration, thermal interference between the adjacent capacitor elements 12a and 12b can be suppressed.

FIG. 3 is a diagram illustrating an example of an inverter circuit. In the inverter circuit 8 shown in FIG. 3, the battery 13 is connected to an MG (motor generator) via each output line. In the inverter circuit 8 shown in FIG. 3, Q is a power transistor, D is a diode, and L is a reactor. The capacitor element 12a is a filter capacitor element, and the capacitor element 12b is a smoothing capacitor element. Is omitted the description of the operation of the inverter circuit 8 shown in FIG. 3, during the operation of the inverter circuit 8, the value of the P ₂ side potential of the P ₁ side potential of the smoothing capacitor element 12b of the filter capacitor element 12a, respectively Different. Usually, in such a case, it is necessary to arrange the filter capacitor element 12a and the smoothing capacitor element 12b with a predetermined interval in order to ensure an insulation distance, and the apparatus becomes large. In this embodiment, when the heat radiating member 14 is arranged between capacitor elements having different potentials such as the filter capacitor element 12a and the smoothing capacitor element 12b, the alumite treatment of the heat radiating member 14 is performed only at the location of the heat radiating member 14 in contact with the refrigerant. It is preferable that the entire heat dissipating member 14 be anodized. As a result, insulation between capacitor elements having different potentials can be ensured, and therefore the distance between the capacitor elements can be shortened (as shown in FIG. The device may be abutted), and the device can be downsized.

  FIG. 4 is a schematic cross-sectional view showing another example of the configuration of the capacitor according to the embodiment of the present invention. In the capacitor 3 shown in FIG. 4, the same reference numerals are given to the same configurations as those of the capacitor 1 shown in FIG. As shown in FIG. 4, the heat radiating member 14 is installed on the core portion 24 of the capacitor element 12 accommodated in the housing 10, and a part of the heat radiating member 14 flows through the cooling portion 22 of the cooler 16. The cooler 16 is inserted into contact with the refrigerant. Further, as described above, an alumite treatment is applied to at least a portion of the heat dissipation member 14 inserted into the cooler 16. As an example of installing the heat radiating member 14 on the core portion 24 of the capacitor element 12, for example, a method in which electrode foils (anode foil and cathode foil) are arranged on both sides of a dielectric film is wound around the heat radiating member 14. That is, by using the heat radiating member 14 as a winding core, the heat radiating member 14 can be disposed on the core portion 24 of the capacitor element 12.

  When a current is passed through the capacitor element 12, the capacitor element 12 generates heat and the temperature of the capacitor element 12 increases. In particular, since it becomes more difficult to dissipate heat to the outside as the core portion 24 of the capacitor element 12, the temperature of the capacitor element 12 that rises due to heat generation becomes higher toward the core portion 24 of the capacitor element 12. . In this embodiment, since the heat radiating member 14 is provided in the core part 24 of the capacitor | condenser element 12, the heat | fever of the capacitor | condenser element 12 can be discharge | released to a refrigerant | coolant via the heat radiating member 14. FIG. In particular, the heat of the core part 24 of the capacitor element 12 whose temperature is increased can be efficiently released to the refrigerant. As a result, the heat dissipation characteristics of the capacitor element 12 can be improved. Moreover, since the heat radiating member 14 is anodized, insulation between the heat radiating member 14 and the refrigerant flowing through the cooler 16, particularly the cooling unit 22, is ensured. As a result, it is possible to suppress the occurrence of a short circuit and leakage current of the capacitor.

  When the capacitor element 12 is fixed to the housing body 10 and the cooler 16, a nut is usually inserted into the core portion 24 of the capacitor element 12, and the partition wall (10 a, 16 a) of the housing body 10 and the cooler 16 is inserted. A threaded portion is formed. Then, a fastener such as a bolt is inserted into the housing 10 and the threaded portion of the partition wall (10a, 16a) of the cooler 16 and the nut of the core portion 24 to be screwed. In such a configuration, when the screw is fixed, a mechanical force acts on the capacitor element 12, and the capacitor element 12 may be damaged. FIG. 5 is a schematic cross-sectional view showing another example of the configuration of the capacitor according to the embodiment of the present invention. FIG. 6 is a schematic view showing a portion of the heat radiating member inserted into the cooler shown in FIG. In addition to the configuration of the capacitor 3 shown in FIG. 4, the capacitor 4 of the present embodiment is provided with a threaded portion 26 at a position of the heat radiation member 14 inserted into the cooler 16 as shown in FIG. 6. The screw cutting portion 28 provided in the partition wall 16a of the cooler 16 is screwed. The threaded portion 28 provided in the partition wall 16 a is formed in a through-hole of the partition wall 16 a of the cooler 16 provided to insert the heat radiating member 14 into the cooling portion 22 of the cooler 16. The through hole formed in the partition wall 16a of the cooler 16 has a diameter equivalent to the diameter of the heat dissipation member 14 in order to fix the threaded portion 26 formed in the heat dissipation member and the threaded portion 28 provided in the partition wall 16a with screws. It is what has. With the above configuration, it is possible to prevent mechanical force from acting on the capacitor element 12 itself at the time of screw fixing, and thus it is possible to prevent damage to the capacitor element 12.

  In the present embodiment, the heat dissipating member 14 and the cooler 16 are fastened by the threaded portions (26, 28), and the container 10 and the cooler 16 are fastened. Therefore, it is not necessary to fasten the container 10 to the cooler 16 using the fastener 18 such as a bolt shown in FIG. However, in order to secure a strong fastening force between the container 10 and the cooler 16, the container 10 may be fastened to the cooler 16 using a fastener 18 such as a bolt shown in FIG. 4. Good.

  Moreover, in this embodiment, in order to ensure insulation with the heat radiating member 14, the cooler 16, and a refrigerant | coolant, it is preferable that the threading part 26 formed in the heat radiating member 14 is also anodized.

  Moreover, in this embodiment, it is preferable to provide a sealing material in the threaded part 26 formed in the heat radiating member 14. With the above configuration, since airtightness between the heat dissipation member 14 and the cooler 16 (through hole of the cooler 16) can be ensured, the refrigerant in the cooler 16 can be prevented from flowing out. . The sealing material has a certain degree of elasticity in order to improve the airtightness between the heat radiating member 14 and the cooler 16 (the through hole of the cooler 16). For example, a seal tape (adhesive tape), a gasket, etc. Can be mentioned. For example, by winding a sealing tape (adhesive tape) around the threaded portion 26 formed on the heat dissipation member 14, the airtightness between the heat dissipation member 14 and the cooler 16 (through hole of the cooler 16) can be easily increased. Is possible.

  FIG. 7 is a schematic cross-sectional view showing another example of the configuration of the capacitor according to the embodiment of the present invention. In the capacitor 5 shown in FIG. 7, the same reference numerals are given to the same configurations as those of the capacitor 3 shown in FIG. As shown in FIG. 7, heat radiation fins 30 are provided at locations of the heat radiation member 14 that is inserted into the cooler 16. By providing the radiating fins 30, the heat transferred from the capacitor element 12 to the heat radiating member 14 can be efficiently released to the refrigerant, and the heat dissipation characteristics of the capacitor element 12 can be improved.

  In the radiating fin 30 shown in FIG. 7, a plurality of pin fins are arranged perpendicularly to the refrigerant flow direction with a predetermined interval therebetween. The direction of the plurality of fins is not limited to the above, and may be arranged along the flow of the refrigerant, for example. Moreover, the fin shape of the radiation fin 30 is not limited to a pin fin, and is not particularly limited to a straight fin, a wave fin, or the like. However, by providing the heat radiating member 14 with a plurality of pin fins spaced apart from each other and arranged perpendicular to the flow direction of the refrigerant, the refrigerant flowing through the cooling unit 22 can be radiated from the heat radiating fins 30. A turbulent flow is formed at the time of collision, and heat exchange between the refrigerant and the radiation fins 30 is promoted. As a result, the heat dissipation characteristics of the capacitor element 12 can be improved. Moreover, in order to ensure insulation with a cooler, especially a refrigerant | coolant, it is preferable that the radiation fin 30 is also alumite-processed.

  As the capacitor element 12, for example, a capacitor element such as a plastic film capacitor, a ceramic capacitor, an aluminum electrolytic capacitor, or an electric double layer capacitor is used. It is not limited. Capacitor elements for plastic film capacitors and ceramic capacitors are formed, for example, by interposing a dielectric film between an anode foil and a cathode foil and laminating or winding them. A dielectric film of a capacitor element for a plastic film capacitor is made of a resin material such as polyethylene terephthalate, polypropylene, or polyethylene naphthalate. A dielectric film of a capacitor element for a ceramic capacitor is made of a ceramic material such as barium titanate. A capacitor element for an aluminum electrolytic capacitor is formed, for example, by interposing electrolytic paper (separator) between an anode aluminum foil and a cathode aluminum foil and laminating or winding them. A capacitor element for an electric double layer capacitor is formed, for example, by interposing a separator between an anode carbon electrode and a cathode carbon electrode, and laminating or winding them. The capacitor elements for aluminum electrolytic capacitors and electric double layer capacitors are impregnated with an electrolytic solution.

  As described above, in the present embodiment, the heat dissipating member that releases heat from the capacitor element to the cooler side is installed in the capacitor element, and a part of the heat dissipating member is inserted into the cooler so as to be in contact with the refrigerant. Furthermore, by performing alumite treatment at least on the portion of the heat radiating member exposed to the cooling section, it is possible to ensure insulation between the heat radiating member and the cooler, particularly the refrigerant, and to improve the heat radiation characteristics of the capacitor element. As a result, it is possible to suppress a short circuit of the capacitor and a leakage current. In addition, in order to ensure insulation, it is not necessary to arrange insulating materials such as an insulating sheet in a complicated manner, so that it is possible to suppress an increase in cost and size of the capacitor.

It is a schematic cross section which shows an example of a structure of the capacitor | condenser which concerns on embodiment of this invention. It is a schematic cross section which shows another example of a structure of the capacitor | condenser which concerns on embodiment of this invention. It is a figure which shows an example of an inverter circuit. It is a schematic cross section which shows another example of a structure of the capacitor | condenser which concerns on embodiment of this invention. It is a schematic cross section which shows another example of a structure of the capacitor | condenser which concerns on embodiment of this invention. It is a schematic diagram which shows the location of the thermal radiation member penetrated in the cooler shown in FIG. It is a schematic cross section which shows another example of a structure of the capacitor | condenser which concerns on embodiment of this invention. It is a schematic cross section which shows the structure of the conventional capacitor | condenser.

Explanation of symbols

  1-6 capacitor, 8 inverter circuit, 10,36 container, 10a, 16a partition, 12,32 capacitor element, 12a filter capacitor element, 12b smoothing capacitor element, 14 heat dissipation member, 16,38 cooler, 18,44 fastening Tools, 20, 46 O-ring, 22, 40 Cooling part, 24, 42 Core part, 26, 28 Threaded part, 30 Radiation fin, 34 Heat pipe.

Claims (9)

A capacitor having one or a plurality of capacitor elements, a container that houses the capacitor elements and is attached to a cooler, and a heat radiating member that releases heat from the capacitor elements to the cooler side,
The heat radiating member is installed in the capacitor element, and a part of the heat radiating member is inserted into the cooler so as to be in contact with the refrigerant flowing in the cooler,
The capacitor | condenser characterized by the alumite process being performed to the location inserted in the said cooler at least among the said thermal radiation members.   2. The capacitor according to claim 1, wherein the capacitor element is a wound type.   3. The capacitor according to claim 1, wherein the heat dissipating member is installed on an end face of the capacitor element, and the cooler is configured such that a part of the heat dissipating member is in contact with the refrigerant flowing in the cooler. Capacitor that is inserted into the capacitor.   3. The capacitor according to claim 1, wherein the heat dissipating member is disposed between adjacent capacitor elements, and a part of the heat dissipating member is in contact with the refrigerant flowing through the cooler. Capacitor characterized by being inserted into.   3. The capacitor according to claim 2, wherein the heat dissipating member is installed in a core part of the capacitor, and a part of the heat dissipating member is brought into contact with the refrigerant flowing through the cooler. Capacitor that is inserted.   The capacitor according to claim 5, wherein a threaded portion is provided at a position of the heat dissipating member inserted into the cooler.   The capacitor according to claim 6, wherein the threaded portion is anodized.   8. The capacitor according to claim 6, wherein a sealing material is provided at the threaded portion.   6. The capacitor according to claim 5, wherein a heat radiation fin is provided at a position of the heat radiation member inserted into the cooler.

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